Table 1
Hypotheses.
| MECHANISM | TRAINED TASK (ORT) | UNTRAINED STIMULI (SRT) | UNTRAINED PARADIGM (ODT) | ||
|---|---|---|---|---|---|
| QUANTITY | QUALITY | QUANTITY | QUALITY | PERFORMANCE | |
| Capacity | Increase | – | Increase | – | Increase |
| Efficiency: Paradigm-specific expertise | – | Increase | – | Increase | No change |
| Efficiency: Stimulus-specific expertise | – | Increase | – | No change | Increase |
[i] Note: All performance changes are relative to changes observed in the active control group. Hyphens (–) refer to possible concurrent improvements. ORT: orientation-reproduction task; SRT: shape-reproduction task; ODT: orientation-change detection task.
Figure 1
Participant Flow Chart.
Table 2
Participant Demographics as a Function of Groups.
| MEASURE | GROUP | COMPARISON | |||
|---|---|---|---|---|---|
| EXPERIMENTAL | ACTIVE CONTROL | STATISTICAL VALUE | p | BF10 ± ERROR % | |
| Group size: n | 30 | 34 | |||
| Gender: female/male/non-binary | 8/22/0 | 17/17/0 | 2.73 | .098 | 3.40 ± 0.00 |
| Age: M (SD) | 22.73 (3.92) | 21.94 (2.52) | 0.33 | .745 | 1/2.62 ± 0.00 |
[i] Note: Gender differences were tested with a chi-squared test and age differences with Yuen’s t-test.
Figure 2
Training and Transfer Tasks.
Note: Panel A: Orientationreproduction task at set size 4. Panel B: Shape-reproduction task at set size 4. Panel C: Orientation-change detection task at set size 4 in the change condition. Panel D: Visual search task at set size 8 in the change condition.
Table 3
Categorical Labels for Describing the Strength of Bayesian Evidence.
| BAYES FACTORS | CATEGORICAL LABELS | |
|---|---|---|
| H10 | H01 | |
| >100 | <1/100 | Decisive |
| 30 to 100 | 1/100 to 1/30 | Very strong |
| 10 to 30 | 1/30 to 1/10 | Strong |
| 3 to 10 | 1/10 to 1/3 | Substantial |
| 1 to 3 | 1/3 to 1 | Ambiguous |
| 1 | 1 | No evidence |
[i] Note: Adapted from Wetzels and Wagenmakers (2012). H10 = evidence in favour of the alternative hypothesis;
H01 = evidence in favour of the null hypothesis.
Table 4
Descriptive Statistics of Performance During Training.
| MEASURE | TRAINING SESSION | |||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |||||
| M | SD | M | SD | M | SD | M | SD | |
| Experimental Group (n = 30) | ||||||||
| Capacity (K) | ||||||||
| Set Size 2 | 1.88 | 0.15 | 1.88 | 0.19 | 1.89 | 0.12 | 1.89 | 0.16 |
| Set Size 4 | 2.76 | 0.71 | 2.92 | 0.74 | 2.93 | 0.73 | 2.87 | 0.79 |
| Set Size 6 | 2.97 | 1.29 | 3.15 | 1.30 | 3.28 | 1.29 | 3.25 | 1.33 |
| Precision (SD–1) | ||||||||
| Set Size 2 | 0.08 | 0.02 | 0.09 | 0.02 | 0.09 | 0.02 | 0.09 | 0.02 |
| Set Size 4 | 0.06 | 0.02 | 0.07 | 0.02 | 0.07 | 0.02 | 0.07 | 0.02 |
| Set Size 6 | 0.06 | 0.01 | 0.06 | 0.02 | 0.07 | 0.02 | 0.07 | 0.02 |
| Active Control Group (n = 34) | ||||||||
| Accuracy | ||||||||
| Set Size 8 | 0.91 | 0.07 | 0.92 | 0.09 | 0.94 | 0.05 | 0.93 | 0.05 |
| Set Size 16 | 0.84 | 0.07 | 0.84 | 0.10 | 0.87 | 0.08 | 0.86 | 0.08 |
| Set Size 24 | 0.73 | 0.09 | 0.73 | 0.09 | 0.77 | 0.09 | 0.77 | 0.09 |
| RT (ms) | ||||||||
| Set Size 8 | 2056 | 326 | 1998 | 305 | 1890 | 282 | 1918 | 321 |
| Set Size 16 | 2871 | 422 | 2806 | 401 | 2712 | 453 | 2707 | 428 |
| Set Size 24 | 3257 | 468 | 3192 | 452 | 3101 | 499 | 3066 | 447 |
[i] Note: Capacity ranges from 0 to the set size; precision ranges from 0 to ∞. RT = mean reaction time.
Figure 3
Estimates of Capacity and Precision in the Experimental Group Over Four Training Sessions.
Note. Panel A: Estimates of capacity. Panel B: Estimates of precision. Data points with reduced opacity show individual estimates, solid data points represent group means. S1 to S4 = training session 1 to 4.
Table 5
Descriptive Statistics of Cognitive Performance at Pre-Test and Post-Test.
| VARIABLE | GROUP | |||||||
|---|---|---|---|---|---|---|---|---|
| EXPERIMENTAL | ACTIVE CONTROL | |||||||
| PRE-TEST | POST-TEST | PRE-TEST | POST-TEST | |||||
| M | SD | M | SD | M | SD | M | SD | |
| Training tasks | ||||||||
| Orientation reproduction | ||||||||
| Capacity (K) | 2.57 | 0.77 | 2.89 | 0.73 | 2.35 | 0.91 | 2.67 | 0.69 |
| Precision (SD–1) | 0.06 | 0.01 | 0.07 | 0.02 | 0.06 | 0.02 | 0.05 | 0.01 |
| Visual search | ||||||||
| Accuracy | 0.76 | 0.14 | 0.81 | 0.13 | 0.78 | 0.09 | 0.86 | 0.10 |
| RT (ms) | 2973 | 849 | 2985 | 633 | 3101 | 475 | 2636 | 509 |
| Transfer tasks | ||||||||
| Shape reproduction | ||||||||
| Capacity (K) | 2.26 | 0.76 | 2.10 | 0.84 | 2.22 | 0.68 | 2.30 | 0.71 |
| Precision (SD–1) | 0.05 | 0.02 | 0.06 | 0.03 | 0.04 | 0.02 | 0.04 | 0.03 |
| Orientation-Change detection | ||||||||
| Capacity (Pashler’s k) | 2.09 | 1.12 | 2.37 | 0.70 | 2.05 | 0.82 | 2.01 | 0.72 |
[i] Note: Pashler’s k can range from 0 to set size. RT = mean reaction time.
Table 6
Statistical Group Comparisons at Baseline.
| VARIABLE | df | t | P | δt | BF10 ± ERROR % |
|---|---|---|---|---|---|
| Training tasks | |||||
| Orientation reproduction | |||||
| Capacity (K) | 36.72 | 0.51 | .610 | –0.13 | 1/2.42 ± 0.01 |
| Precision (SD–1) | 37.72 | 0.71 | .484 | –0.18 | 1/3.91 ± 0.01 |
| Visual search | |||||
| Accuracy | 29.33 | 0.30 | .766 | 0.08 | 1/2.93 ± 0.01 |
| RT (ms) | 25.34 | 0.01 | .993 | 0.00 | 1/3.06 ± 0.01 |
| Transfer tasks | |||||
| Shape reproduction | |||||
| Capacity (K) | 33.55 | 0.38 | .707 | –0.10 | 1/3.84 ± 0.01 |
| Precision (SD–1) | 38.00 | 1.11 | .274 | –0.28 | 1/2.21 ± 0.01 |
| Orientation-Change detection | |||||
| Capacity (K) | 37.49 | 0.54 | .595 | –0.14 | 1/3.87 ± 0.01 |
Table 7
Analysis of Variance Effects of Training on Cognitive Performance.
| VARIABLE/EFFECT | F | P | BF10 ± ERROR % | ||
|---|---|---|---|---|---|
| Orientation reproduction | |||||
| Capacity | |||||
| Time | 18.12 | <.001 | .04 | .23 | > 100 ± 2.04 |
| Group | 1.53 | .221 | .02 | .02 | 1/1.58 ± 1.89 |
| Time × Group | 0.00 | .974 | <.01 | <.01 | 1/4.25 ± 3.26 |
| Precision | |||||
| Time | 3.05 | .086 | .01 | .05 | 1/2.78 ± 2.21 |
| Group | 5.68 | .020 | .07 | .08 | 2.87 ± 1.60 |
| Time × Group | 25.63 | <.001 | .07 | .29 | > 100 ± 4.11 |
| Visual search | |||||
| Accuracy | |||||
| Time | 24.79 | <.001 | .08 | .29 | > 100 ± 0.84 |
| Group | 2.55 | .116 | .03 | .04 | 1/1.23 ± 2.06 |
| Time × Group | 1.55 | .218 | .01 | .02 | 1/2.03 ± 4.33 |
| Reaction time | |||||
| Time | 8.22 | .006 | .03 | .12 | 6.61 ± 0.99 |
| Group | 0.67 | .417 | .01 | .01 | 1/2.80 ± 2.08 |
| Time × Group | 9.09 | .004 | .04 | .13 | 10.96 ± 2.40 |
| Shape reproduction | |||||
| Capacity | |||||
| Time | 0.15 | .704 | <.01 | <.01 | 1/5.18 ± 1.28 |
| Group | 0.28 | .596 | <.01 | <.01 | 1/3.31 ± 0.98 |
| Time × Group | 1.36 | .249 | .01 | .02 | 1/2.23 ± 3.69 |
| Precision | |||||
| Time | 1.12 | .293 | .01 | .02 | 1/3.47 ± 1.05 |
| Group | 4.72 | .034 | .05 | .07 | 1.63 ± 0.80 |
| Time × Group | 1.72 | .195 | .01 | .03 | 1/1.90 ± 2.33 |
| Orientation-Change detection | |||||
| Capacity | |||||
| Time | 1.83 | 0.181 | 0.01 | 0.03 | 1/2.79 ± 1.00 |
| Group | 1.06 | 0.306 | 0.01 | 0.02 | 1/1.98 ± 0.55 |
| Time × Group | 3.12 | 0.082 | 0.01 | 0.05 | 1/1.05 ± 2.56 |
[i] Note: BF10 = Bayes factor in favour of the alternative hypothesis. Degrees of freedom df1 and df2 were 1, 62 respectively.
Figure 4
Pre-Post Changes in the Visual WM Training Task on Capacity and Precision.
Note: Panel A: Changes in capacity. Panel B: Changes in precision. Left: Small transparent data points show the mean values for each individual. Big solid data points show the mean values at group level, with the error bars representing standard errors. Right: Density distributions of the data for both groups.
Figure 5
Density of Pre-Post Responses Changes Differs Between Groups.
Note: Purple histograms with dashed lines show the density of each response at pre-test, and the pink histograms with solid lines show the density of each response at post-test. Number of bins: 60. Experimental group: n = 30; active control group: n = 34; total responses per participant was 120 each at pre-test and post-test.